The present invention relates generally to medical devices, and more particularly to a catheter for delivery of an agent to the coronary or peripheral vasculature.
In the treatment of diseased vasculature, therapeutic agents have commonly been administered, typically as part of other interventional therapies such as angioplasty or stent delivery. Local, as opposed to systemic delivery is a preferred method of treatment in that smaller total levels of medication are administered in comparison to systemic dosages, yet are concentrated at a specific site. As a result, local delivery produces fewer side effects and achieves more effective results.
A variety of methods and devices have been proposed for percutaneous drug delivery to a diseased region of the vasculature. For example, the catheter shaft can have a drug delivery lumen which extends to a port in the distal end of the catheter, and which is connected at the proximal end to a fluid source containing the drug. In catheters having porous balloons, the drug can be infused either through the inflation lumen or a separate, dedicated drug delivery lumen in the catheter shaft, into the inflatable interior of the porous balloon and through the porous wall of the balloon.
In order to properly position the distal end of a drug delivery catheter in a patient's tortuous distal vasculature, the catheter should preferably have good force transmission, and a low-profile, flexible distal section, to advance within the patient's body lumen. The catheter is typically advanced into position by pushing the proximal end of the catheter and tracking the catheter over a guidewire. However, one difficulty has been providing a drug delivery catheter with a relatively large drug delivery lumen for infusion of the drug, which is nonetheless highly maneuverable (e.g., pushability and trackability) to facilitate positioning the catheter at the desired treatment location in the patient's vasculature.